Thank you everyone for your help on this. I should have backed up the file before I synced the file. I do have a separate files for all media I put on my tree, so that part of the recovery is okay, just a pain having to load it all again. Also have plenty of space as have a 600 gigabyte external drive and back up everything to this as well as from laptop to PC.
Yesterday I did a backup before treesync, so will wait and see if it works this time.
Valuable lesson learnt here as well, Backup, backup backup.